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Finding the Fourth Proportional to 75.28, 112.80 and 54.72

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Solution

The fourth proportional to 75.28, 112.80 and 54.72 is: 81.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.28 : 112.80 = 54.72 : x
  2. Step 2: Convert to fraction form
    75.28/112.80 = 54.72/x
  3. Step 3: Cross multiply
    75.28x = 112.80 × 54.72
  4. Step 4: Simplify right side
    75.28x = 6,172.42
  5. Step 5: Solve for x
    x = 6,172.42/75.28
  6. Step 6: Final answer
    x = 81.99

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.